Kiln seal

ABSTRACT

A sealing assembly for sealing the opening between a pair of communicating members such as a rotary kiln and the feed end housing or fire hood of the kiln. The seal comprises a plurality of abradable sealing blocks which are in slight engagement with the rotating member or kiln. These sealing blocks are spring biased toward the kiln and guide means are provided for guiding the blocks radially inwardly toward the kiln as they wear. The ends of the blocks are arranged so that adjacent blocks overlap to insure a continuous seal around the kiln.

United States Patent Talago 1 Oct. 24, 1972 [54] KILN SEAL [72] Inventor: Paul Talago, Center Valley, Pa. Primary Camby Attorney-Jack L. Prather et al. [73] Assignee: Fuller Company 1 22 Filed: June 18, 1971 [57] ABSTRACT I A sealing assembly for sealing the opening between a [211 App]? 154577 pair of communicating members such as a rotary kiln and thefeed end housing or fire hood of the kiln. The [52] U5. Cl. ..263/32R Seal comprises a p ur ity f a rada l s aling locks 5 1] Int. Cl ..F27b 7/24 which are in slight engagement with the rotating [58 Field of Search ..263/32 R, 33 R; 34/142 member or kiln- These sealing blocks are spring biased toward the kiln and guide means are provided for [56] References Cited guiding the blocks radially inwardly toward the kiln as they wear. The ends of the blocks are arranged so that UNITED STATES PATENTS adjacent blocks overlap to insure a continuous seal 1,895,348 1/1933 Schlegel et al. ..263/32 R ammd the 4/1971 McDowell ..263/32 R 9 Claims, 6 Drawing Figures PATENIEUWZ4 M v 3.700.220 I same [If 2- )INVENTORI PA u 1. TA LAGO KILN SEAL BACKGROUND OF THE INVENTION The present invention relates to a sealing assembly for sealing the opening between communicating members one of which rotates relative to the other. More particularly the invention relates to a sealing assembly for sealing the opening between a rotating member such as a rotary kiln or dryer and a stationary member such as a fire hood or feed end housing.

In particular, the present invention is an improvement over U. S. Pat. No. 3,575,397 issued to D. M. Mc- Dowell et al. In the McDowell et al patent there is provided a sealing assembly for a rotary kiln or dryer shell which includes a plurality of spring biased abradable sealing blocks with an arrangement for preventing axial movement of the sealing blocks relative to a fixed housing and a wedge arrangement which permits and guides radial movement of the blocks toward the rotating member as the blocks wear.

The seal of the McDowell et a1 patent provides a seal for a rotary furnace such as a rotary kiln which insures good sealing and minimizes repair and maintenance by providing easy replacement of worn sealing elements. The individual sealing elements can be replaced without replacement of the entire seal in the event of uneven wear on the seal.

Although the apparatus shown in the above mentioned patent has proved to be satisfactory for many applications, such apparatus does have one particular disadvantage. In the apparatus shown in the McDowell et al patent, the sealing blocks are arranged so that there is inherently a space between adjacent blocks. Regardless of how close tolerances are kept, some space will be present and leakage through this space will often occur. In many applications, it is undesirable to have any amount of leakage.

Other sealing arrangements for rotary kilns and dryers have been provided but to my knowledge, all prior sealing assemblies for such use have permitted a certain amount of leakage by the fact that there is a space between adjacent abradable sealing members.

SUMMARY It is the principal object of this invention to provide a novel sealing assembly for use in sealing an opening between two communicating members which substantially eliminates leakage through the opening between such members.

It is a further object of this invention to provide a sealing assembly for use in sealing an opening between a rotating cylindrical member and a stationary member which has advantageous wear qualities and permits early replacement of the wearing parts of the seal and substantially eliminates leakage through the seal.

In general, the foregoing and other objects will be carried out by providing a sealing assembly for sealing the opening between two communicating members comprising a plurality of sealing blocks extending about the perimeter of one of the members; means secured to the other member for confining the sealing blocks so as to substantially prevent axial movement while permitting radial movement of the sealing blocks; means for biasing the sealing blocks radially toward said one of the members for maintaining a sliding contact therebetween; the edges of said sealing blocks near said one of the members at least partially overlapping the adjacent blocks to thereby provide a continuous seal around said one of the members.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described .in connection with the accompanying drawings wherein:

FIG. 1 is an elevational view of a rotary kiln and associated equipment which may employ the present invention;

FIG. 2 is a fragmentary plan view of a portion of the seal of the present invention;

FIG. 3 is a sectional view of the seal of the present invention taken on the line 3-3 of FIG. 2;

FIG. 4 is a fragmentary view taken on the line 4-4 of FIG. 3 showing a portion of the seal of the present invention;

FIG. 5 is a view of a component of the seal of the present invention; and

FIG. 6 is a view of another component of the seal of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The invention will be described in connection with use on a rotary kiln but it should be understood that the sealing assembly of the present invention may be employed wherever it is desired to provide a seal between rotating and nonrotating communicating members.

Referring to FIG. 1, there is shown a rotary kiln 10 with a feed end housing 11 and a fire hood 12. The invention will be described as it is used between the kiln 10 and the feed end housing 11. Referring to FIG. 3, it will be seen that the kiln 10 extends through an opening 14 in the feed end housing 11. It is the object of this invention to provide a seal which prevents leakage through the openingl4 around the kiln shell 10.

The seal includes an annular ring member 16 secured to the stationary feed end. housing 11 by any suitable means such as welding. The ring 16 is provided with a plurality of spaced apart raised portions 18 around its face. The portions 18 may be formed as separate pieces from the ring 16 and suitably secured to the ring 16 as by welding. The raised portions 18 are best shown in FIG. 6 and include side walls 20 which are angled downwardly and inwardly from the top of the ring 16 so that the portion 18 is wedge shaped.

A plurality of abradable blocks generally designated 22 which are rectangular and have parallel edges 24 are arranged around the perimeter of the kiln shell 10. The raised portions 18 are spaced apart a distance such that alternate sealing blocks 22a will fit between these raised portions. There is sufficient clearance between the raised portion and sealing blocks to permit the sealing blocks 22a to slide radially with respect to the ring 16. The remaining sealing blocks 22b are positioned forwardly of the raised portions 18. Preferably, the blocks 22a and 22b have the same physical dimensions to permit interchangeability.

The blocks are held in position by retaining plates 30 which are secured to the annular ring 16 by nuts and bolts 32. In the preferred form, the raised portions 18 are slightly thicker, say one-sixteenth to one-eighth inch, than the blocks 22 to permit radial movement of the blocks without interference. The retaining plates 30 block 22b. The forward arm 36 of the plates 30 confine Y the blocks 22b to prevent forward axial movement of these blocks and the rearward arm 37 of the plates 30 prevent forward axial movement of the blocks 22a. The

ring 16 prevents rearward axial movement of the blocks 22.

As shown in FIG. 3, the ring 16 is mounted on the feed end housing 11 so that it is spaced from the opening 14. The blocks 22 extend downwardly to contact the shell 10. The staggered positioning of the sealing blocks 22a and 22b permits the edges 24 of adjacent sealing blocks to overlap as indicated at 26 in FIG. 2.

As with the McDowell et al patent previously mentioned, the blocks 22 are provided with a means for biasing the blocks toward the kiln shell 10. The biasing means includes a triangular shaped spring support 40 having a stop 41 and feet 42 which engage the top of thesealing blocks 22. The stop 41 serves to prevent the support 40 from jamming.

The spring support'40 is biased inwardly by means of a a garter spring. Inthe preferred form, a plurality of spaced apart'eyes 46 are secured to the ring 16 as shown in FIGS. 2 and 3 and an individual spring 48 extends from one eye 46 through a guide 47 in the top of the triangular shaped spring support 40 to the next eye 46.. In this manner, if uneven wear on an individual sealing block 22 should occur, the sealing block will be biased toward the shell to insure that no leakage occurs. In addition, if it is desired to replace a block 22 which has wornv more than the other blocks,,then by disconnecting the individual spring 48 and removing the support 40 such block can be removed .without disturbing the remaining sealing blocks.

The sealing blocks 22 are preferably made of a relatively heat resistant abradable material such as graphite which is self-lubricating and minimizes the generation of heat.

From the foregoing it should be apparent that the objects of the present invention have been carried out. The sealing blocks are arranged so that they overlap a slight amount as indicated at 26 to prevent leakage in the area between adjacent blocks. Each of the blocks are radially guided as they move radially toward the shell 10 as wear occurs. Some of the blocks are guided by the wall or leg 34 of the retaining plate 30 while the remaining blocks are guided by the ends of the raised portion 18. Axial movement of the sealing blocks is prevented by the stationary, ring 16 and stationary retaining plates 30. l

Although the seal of the present invention has been described as being fixed to the stationary member of a pair of communicating members, it is possible to use the present invention by fixing the seal to a rotating member. For example, the feed to a rotary kiln could be a cylindrical member concentric with and extending into the kiln. In this situation, the seal ring 16 could be fixed to the rotating kiln and the blocks biased into contact with the stationary feed member. Also if desired, the blocks could be arranged to engage the inside of a cylindrical member rather than the outside.

It is intended that the foregoing description be merely that of a preferred embodiment and that the invention be limited solely by that which IS within the scope of the appended claims.

Iclaim:

l. A sealing assembly for sealing the opening between two communicating members comprising a plurality of sealing blocks extending about the perimeter of one of the members; means secured to the other member for confining the sealing blocks so as to sub stantially. prevent axial movement while permitting radial movement of the sealing blocks; means for biasing the sealing blocks radially toward said one of the members for maintaining a sliding contact therebetween; the edges of said sealing blocks near said one of the members at least partially overlapping the adjacent blocks to thereby provide a continuous seal around said one of the members.

2. The sealing assembly of claim 1 further comprising means for guiding the radial movement of said sealing blocks. v

3. The sealing assembly of claim 2 wherein at least one of the members is cylindrical and at least one of the members rotates and the sealing blocks extend around the perimeter of the cylindrical member.

4. The sealing assembly of ,claim 2 wherein said means for guiding radial movement of said sealing blocks includes a plurality of spaced-apart wedgeshaped members secured to said means for confining the sealing blocks.

5. The sealing assembly of claim 4 wherein said means for confining the sealing blocks includes an annular ring secured to the other member and said wedge-shaped members are integral with said annular ring.

6. The sealing assembly of claim 4 wherein said means for guiding radial movement of said sealing blocks further includes a plurality of spaced-apart retaining plates secured to said means for confining the sealing blocks; each of said retaining plates having a wall for engaging and guiding one of said sealing blocks.

7. The sealing assembly of claim 6 wherein the wedge means secured to the means for retaining the sealing blocks are positioned to guide alternate sealing blocks and the retaining plates are positioned to guide the remaining sealing blocks.

8. The sealing assembly of claim 7 wherein at least one of said members is cylindrical and at least one of said members rotates and said sealing blocks extend around the periphery of the cylindrical members.

9. The sealing assembly of claim 8 wherein each of said sealing blocks has parallel sides and said retaining plates are Z-shaped to definesaid wall for engaging and guiding the sealing block. 

1. A sealing assembly for sealing the opening between two communicating members comprising a plurality of sealing blocks extending about the perimeter of one of the members; means secured to the other member for confining the sealing blocks so as to substantially prevent axial movement while permitting radial movement of the sealing blocks; means for biasing the sealing blocks radially toward said one of the members for maintaining a sliding contact therebetween; the edges of said sealing blocks near said one of the members at least partially overlapping the adjacent blocks to thereby provide a continuous seal around said one of the members.
 2. The sealing assembly of claim 1 further comprising means for guiding the radial movement of said sealing blocks.
 3. The sealing assembly of claim 2 wherein at least one of the members is cylindrical and at least one of the members rotates and the sealing blocks extend around the perimeter of the cylindrical member.
 4. The sealing assembly of claim 2 wherein said means for guiding radial movement of said sealing blocks includes a plurality of spaced-apart wedge-shaped members secured to said means for confining the sealing blocks.
 5. The sealiNg assembly of claim 4 wherein said means for confining the sealing blocks includes an annular ring secured to the other member and said wedge-shaped members are integral with said annular ring.
 6. The sealing assembly of claim 4 wherein said means for guiding radial movement of said sealing blocks further includes a plurality of spaced-apart retaining plates secured to said means for confining the sealing blocks; each of said retaining plates having a wall for engaging and guiding one of said sealing blocks.
 7. The sealing assembly of claim 6 wherein the wedge means secured to the means for retaining the sealing blocks are positioned to guide alternate sealing blocks and the retaining plates are positioned to guide the remaining sealing blocks.
 8. The sealing assembly of claim 7 wherein at least one of said members is cylindrical and at least one of said members rotates and said sealing blocks extend around the periphery of the cylindrical members.
 9. The sealing assembly of claim 8 wherein each of said sealing blocks has parallel sides and said retaining plates are Z-shaped to define said wall for engaging and guiding the sealing block. 